The overall objectives of this resource are to develop the technology of NMR imaging and spectroscopy in vivo and to apply these developments to the study of significant biomedical problems. Potential applications are diverse and require collaboration between NMR specialists and a variety of basic scientists and biomedical professionals. The Resource objectives will be carried out through a program of research and development in three cores and an additional technical-support core which serves five collaborative and four service projects. The technical research and development cores are: (1) RF coil development, (2) Methods of imaging and localized spectroscopy, and (3) Magnetic gradient systems. The current and proposed collaborative projects are studies in (1) 1H imaging of fetal neural tissue transplants, (2) 31P clinical spectroscopy applied to the measurement of osteosarcomas in humans, (3) 31P spectroscopy of human osteosarcomas implanted in nude mice, (4) 1H imaging and 1H and 31P spectroscopy of developmental embryology, and (5) 1H imaging of experimental optic neuritis.